/* -*- Mode: c++; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 40; -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "GLUploadHelpers.h"

#include "GLContext.h"
#include "mozilla/gfx/2D.h"
#include "gfxUtils.h"
#include "mozilla/gfx/Tools.h"  // For BytesPerPixel
#include "nsRegion.h"
#include "GfxTexturesReporter.h"
#include "mozilla/gfx/Logging.h"

namespace mozilla {

using namespace gfx;

namespace gl {

static unsigned int
DataOffset(const IntPoint& aPoint, int32_t aStride, SurfaceFormat aFormat)
{
  unsigned int data = aPoint.y * aStride;
  data += aPoint.x * BytesPerPixel(aFormat);
  return data;
}

static GLint GetAddressAlignment(ptrdiff_t aAddress)
{
    if (!(aAddress & 0x7)) {
       return 8;
    } else if (!(aAddress & 0x3)) {
        return 4;
    } else if (!(aAddress & 0x1)) {
        return 2;
    } else {
        return 1;
    }
}

// Take texture data in a given buffer and copy it into a larger buffer,
// padding out the edge pixels for filtering if necessary
static void
CopyAndPadTextureData(const GLvoid* srcBuffer,
                      GLvoid* dstBuffer,
                      GLsizei srcWidth, GLsizei srcHeight,
                      GLsizei dstWidth, GLsizei dstHeight,
                      GLsizei stride, GLint pixelsize)
{
    unsigned char* rowDest = static_cast<unsigned char*>(dstBuffer);
    const unsigned char* source = static_cast<const unsigned char*>(srcBuffer);

    for (GLsizei h = 0; h < srcHeight; ++h) {
        memcpy(rowDest, source, srcWidth * pixelsize);
        rowDest += dstWidth * pixelsize;
        source += stride;
    }

    GLsizei padHeight = srcHeight;

    // Pad out an extra row of pixels so that edge filtering doesn't use garbage data
    if (dstHeight > srcHeight) {
        memcpy(rowDest, source - stride, srcWidth * pixelsize);
        padHeight++;
    }

    // Pad out an extra column of pixels
    if (dstWidth > srcWidth) {
        rowDest = static_cast<unsigned char*>(dstBuffer) + srcWidth * pixelsize;
        for (GLsizei h = 0; h < padHeight; ++h) {
            memcpy(rowDest, rowDest - pixelsize, pixelsize);
            rowDest += dstWidth * pixelsize;
        }
    }
}

// In both of these cases (for the Adreno at least) it is impossible
// to determine good or bad driver versions for POT texture uploads,
// so blacklist them all. Newer drivers use a different rendering
// string in the form "Adreno (TM) 200" and the drivers we've seen so
// far work fine with NPOT textures, so don't blacklist those until we
// have evidence of any problems with them.
bool
CanUploadSubTextures(GLContext* gl)
{
    if (!gl->WorkAroundDriverBugs())
        return true;

    // There are certain GPUs that we don't want to use glTexSubImage2D on
    // because that function can be very slow and/or buggy
    if (gl->Renderer() == GLRenderer::Adreno200 ||
        gl->Renderer() == GLRenderer::Adreno205)
    {
        return false;
    }

    // On PowerVR glTexSubImage does a readback, so it will be slower
    // than just doing a glTexImage2D() directly. i.e. 26ms vs 10ms
    if (gl->Renderer() == GLRenderer::SGX540 ||
        gl->Renderer() == GLRenderer::SGX530)
    {
        return false;
    }

    return true;
}

static void
TexSubImage2DWithUnpackSubimageGLES(GLContext* gl,
                                    GLenum target, GLint level,
                                    GLint xoffset, GLint yoffset,
                                    GLsizei width, GLsizei height,
                                    GLsizei stride, GLint pixelsize,
                                    GLenum format, GLenum type,
                                    const GLvoid* pixels)
{
    gl->fPixelStorei(LOCAL_GL_UNPACK_ALIGNMENT,
                     std::min(GetAddressAlignment((ptrdiff_t)pixels),
                              GetAddressAlignment((ptrdiff_t)stride)));
    // When using GL_UNPACK_ROW_LENGTH, we need to work around a Tegra
    // driver crash where the driver apparently tries to read
    // (stride - width * pixelsize) bytes past the end of the last input
    // row. We only upload the first height-1 rows using GL_UNPACK_ROW_LENGTH,
    // and then we upload the final row separately. See bug 697990.
    int rowLength = stride/pixelsize;
    gl->fPixelStorei(LOCAL_GL_UNPACK_ROW_LENGTH, rowLength);
    gl->fTexSubImage2D(target,
                       level,
                       xoffset,
                       yoffset,
                       width,
                       height-1,
                       format,
                       type,
                       pixels);
    gl->fPixelStorei(LOCAL_GL_UNPACK_ROW_LENGTH, 0);
    gl->fTexSubImage2D(target,
                       level,
                       xoffset,
                       yoffset+height-1,
                       width,
                       1,
                       format,
                       type,
                       (const unsigned char*)pixels+(height-1)*stride);
    gl->fPixelStorei(LOCAL_GL_UNPACK_ALIGNMENT, 4);
}

static void
TexSubImage2DWithoutUnpackSubimage(GLContext* gl,
                                   GLenum target, GLint level,
                                   GLint xoffset, GLint yoffset,
                                   GLsizei width, GLsizei height,
                                   GLsizei stride, GLint pixelsize,
                                   GLenum format, GLenum type,
                                   const GLvoid* pixels)
{
    // Not using the whole row of texture data and GL_UNPACK_ROW_LENGTH
    // isn't supported. We make a copy of the texture data we're using,
    // such that we're using the whole row of data in the copy. This turns
    // out to be more efficient than uploading row-by-row; see bug 698197.

    // Width and height are never more than 16384. At 16Ki*16Ki, 4Bpp is 1GiB, but
    // if we allow 8Bpp (16-bit channels, or higher) here, that's 2GiB+, which would
    // overflow on 32-bit.
    MOZ_ASSERT(width <= 16384);
    MOZ_ASSERT(height <= 16384);
    MOZ_ASSERT(pixelsize < 8);

    const auto size = CheckedInt<size_t>(width) * height * pixelsize;
    if (!size.isValid()) {
      // This should never happen, but we use a defensive check.
      MOZ_ASSERT_UNREACHABLE("Unacceptable size calculated.!");
      return;
    }

    unsigned char* newPixels = new (fallible) unsigned char[size.value()];

    if (newPixels) {
        unsigned char* rowDest = newPixels;
        const unsigned char* rowSource = (const unsigned char*)pixels;
        for (int h = 0; h < height; h++) {
            memcpy(rowDest, rowSource, width*pixelsize);
            rowDest += width*pixelsize;
            rowSource += stride;
        }

        stride = width*pixelsize;
        gl->fPixelStorei(LOCAL_GL_UNPACK_ALIGNMENT,
                         std::min(GetAddressAlignment((ptrdiff_t)newPixels),
                                  GetAddressAlignment((ptrdiff_t)stride)));
        gl->fTexSubImage2D(target,
                           level,
                           xoffset,
                           yoffset,
                           width,
                           height,
                           format,
                           type,
                           newPixels);
        delete [] newPixels;
        gl->fPixelStorei(LOCAL_GL_UNPACK_ALIGNMENT, 4);

    } else {
        // If we did not have sufficient memory for the required
        // temporary buffer, then fall back to uploading row-by-row.
        const unsigned char* rowSource = (const unsigned char*)pixels;

        gl->fPixelStorei(LOCAL_GL_UNPACK_ALIGNMENT,
                         std::min(GetAddressAlignment((ptrdiff_t)pixels),
                                  GetAddressAlignment((ptrdiff_t)stride)));

        for (int i = 0; i < height; i++) {
            gl->fTexSubImage2D(target, level,
                               xoffset, yoffset + i,
                               width, 1,
                               format, type, rowSource);
            rowSource += stride;
        }

        gl->fPixelStorei(LOCAL_GL_UNPACK_ALIGNMENT, 4);
    }
}

static void
TexSubImage2DHelper(GLContext* gl,
                    GLenum target, GLint level,
                    GLint xoffset, GLint yoffset,
                    GLsizei width, GLsizei height, GLsizei stride,
                    GLint pixelsize, GLenum format,
                    GLenum type, const GLvoid* pixels)
{
    if (gl->IsGLES()) {
        if (stride == width * pixelsize) {
            gl->fPixelStorei(LOCAL_GL_UNPACK_ALIGNMENT,
                             std::min(GetAddressAlignment((ptrdiff_t)pixels),
                                      GetAddressAlignment((ptrdiff_t)stride)));
            gl->fTexSubImage2D(target,
                               level,
                               xoffset,
                               yoffset,
                               width,
                               height,
                               format,
                               type,
                               pixels);
            gl->fPixelStorei(LOCAL_GL_UNPACK_ALIGNMENT, 4);
        } else if (gl->IsExtensionSupported(GLContext::EXT_unpack_subimage)) {
            TexSubImage2DWithUnpackSubimageGLES(gl, target, level, xoffset, yoffset,
                                                width, height, stride,
                                                pixelsize, format, type, pixels);

        } else {
            TexSubImage2DWithoutUnpackSubimage(gl, target, level, xoffset, yoffset,
                                              width, height, stride,
                                              pixelsize, format, type, pixels);
        }
    } else {
        // desktop GL (non-ES) path
        gl->fPixelStorei(LOCAL_GL_UNPACK_ALIGNMENT,
                         std::min(GetAddressAlignment((ptrdiff_t)pixels),
                                  GetAddressAlignment((ptrdiff_t)stride)));
        int rowLength = stride/pixelsize;
        gl->fPixelStorei(LOCAL_GL_UNPACK_ROW_LENGTH, rowLength);
        gl->fTexSubImage2D(target,
                           level,
                           xoffset,
                           yoffset,
                           width,
                           height,
                           format,
                           type,
                           pixels);
        gl->fPixelStorei(LOCAL_GL_UNPACK_ROW_LENGTH, 0);
        gl->fPixelStorei(LOCAL_GL_UNPACK_ALIGNMENT, 4);
    }
}

static void
TexImage2DHelper(GLContext* gl,
                 GLenum target, GLint level, GLint internalformat,
                 GLsizei width, GLsizei height, GLsizei stride,
                 GLint pixelsize, GLint border, GLenum format,
                 GLenum type, const GLvoid* pixels)
{
    if (gl->IsGLES()) {

        NS_ASSERTION(format == (GLenum)internalformat,
                    "format and internalformat not the same for glTexImage2D on GLES2");

        MOZ_ASSERT(width >= 0 && height >= 0);
        if (!CanUploadNonPowerOfTwo(gl)
            && (stride != width * pixelsize
            || !IsPowerOfTwo((uint32_t)width)
            || !IsPowerOfTwo((uint32_t)height))) {

            // Pad out texture width and height to the next power of two
            // as we don't support/want non power of two texture uploads
            GLsizei paddedWidth = RoundUpPow2((uint32_t)width);
            GLsizei paddedHeight = RoundUpPow2((uint32_t)height);

            // Width and height are never more than 16384. At 16Ki*16Ki, 4Bpp
            // is 1GiB, but if we allow 8Bpp (or higher) here, that's 2GiB,
            // which would overflow on 32-bit.
            MOZ_ASSERT(width <= 16384);
            MOZ_ASSERT(height <= 16384);
            MOZ_ASSERT(pixelsize < 8);

            const auto size =
                CheckedInt<size_t>(paddedWidth) * paddedHeight * pixelsize;
            if (!size.isValid()) {
              // This should never happen, but we use a defensive check.
              MOZ_ASSERT_UNREACHABLE("Unacceptable size calculated.!");
              return;
            }

            GLvoid* paddedPixels = new unsigned char[size.value()];

            // Pad out texture data to be in a POT sized buffer for uploading to
            // a POT sized texture
            CopyAndPadTextureData(pixels, paddedPixels, width, height,
                                  paddedWidth, paddedHeight, stride, pixelsize);

            gl->fPixelStorei(LOCAL_GL_UNPACK_ALIGNMENT,
                             std::min(GetAddressAlignment((ptrdiff_t)paddedPixels),
                                      GetAddressAlignment((ptrdiff_t)paddedWidth * pixelsize)));
            gl->fTexImage2D(target,
                            border,
                            internalformat,
                            paddedWidth,
                            paddedHeight,
                            border,
                            format,
                            type,
                            paddedPixels);
            gl->fPixelStorei(LOCAL_GL_UNPACK_ALIGNMENT, 4);

            delete[] static_cast<unsigned char*>(paddedPixels);
            return;
        }

        if (stride == width * pixelsize) {
            gl->fPixelStorei(LOCAL_GL_UNPACK_ALIGNMENT,
                             std::min(GetAddressAlignment((ptrdiff_t)pixels),
                                      GetAddressAlignment((ptrdiff_t)stride)));
            gl->fTexImage2D(target,
                            border,
                            internalformat,
                            width,
                            height,
                            border,
                            format,
                            type,
                            pixels);
            gl->fPixelStorei(LOCAL_GL_UNPACK_ALIGNMENT, 4);
        } else {
            // Use GLES-specific workarounds for GL_UNPACK_ROW_LENGTH; these are
            // implemented in TexSubImage2D.
            gl->fTexImage2D(target,
                            border,
                            internalformat,
                            width,
                            height,
                            border,
                            format,
                            type,
                            nullptr);
            TexSubImage2DHelper(gl,
                                target,
                                level,
                                0,
                                0,
                                width,
                                height,
                                stride,
                                pixelsize,
                                format,
                                type,
                                pixels);
        }
    } else {
        // desktop GL (non-ES) path

        gl->fPixelStorei(LOCAL_GL_UNPACK_ALIGNMENT,
                         std::min(GetAddressAlignment((ptrdiff_t)pixels),
                                  GetAddressAlignment((ptrdiff_t)stride)));
        int rowLength = stride/pixelsize;
        gl->fPixelStorei(LOCAL_GL_UNPACK_ROW_LENGTH, rowLength);
        gl->fTexImage2D(target,
                        level,
                        internalformat,
                        width,
                        height,
                        border,
                        format,
                        type,
                        pixels);
        gl->fPixelStorei(LOCAL_GL_UNPACK_ROW_LENGTH, 0);
        gl->fPixelStorei(LOCAL_GL_UNPACK_ALIGNMENT, 4);
    }
}

SurfaceFormat
UploadImageDataToTexture(GLContext* gl,
                         unsigned char* aData,
                         int32_t aStride,
                         SurfaceFormat aFormat,
                         const nsIntRegion& aDstRegion,
                         GLuint aTexture,
                         const gfx::IntSize& aSize,
                         size_t* aOutUploadSize,
                         bool aNeedInit,
                         GLenum aTextureUnit,
                         GLenum aTextureTarget)
{
    gl->MakeCurrent();
    gl->fActiveTexture(aTextureUnit);
    gl->fBindTexture(aTextureTarget, aTexture);

    GLenum format = 0;
    GLenum internalFormat = 0;
    GLenum type = 0;
    int32_t pixelSize = BytesPerPixel(aFormat);
    SurfaceFormat surfaceFormat = gfx::SurfaceFormat::UNKNOWN;

    MOZ_ASSERT(gl->GetPreferredARGB32Format() == LOCAL_GL_BGRA ||
               gl->GetPreferredARGB32Format() == LOCAL_GL_RGBA);

    switch (aFormat) {
        case SurfaceFormat::B8G8R8A8:
            if (gl->GetPreferredARGB32Format() == LOCAL_GL_BGRA) {
              format = LOCAL_GL_BGRA;
              surfaceFormat = SurfaceFormat::R8G8B8A8;
              type = LOCAL_GL_UNSIGNED_INT_8_8_8_8_REV;
            } else {
              format = LOCAL_GL_RGBA;
              surfaceFormat = SurfaceFormat::B8G8R8A8;
              type = LOCAL_GL_UNSIGNED_BYTE;
            }
            internalFormat = LOCAL_GL_RGBA;
            break;
        case SurfaceFormat::B8G8R8X8:
            // Treat BGRX surfaces as BGRA except for the surface
            // format used.
            if (gl->GetPreferredARGB32Format() == LOCAL_GL_BGRA) {
              format = LOCAL_GL_BGRA;
              surfaceFormat = SurfaceFormat::R8G8B8X8;
              type = LOCAL_GL_UNSIGNED_INT_8_8_8_8_REV;
            } else {
              format = LOCAL_GL_RGBA;
              surfaceFormat = SurfaceFormat::B8G8R8X8;
              type = LOCAL_GL_UNSIGNED_BYTE;
            }
            internalFormat = LOCAL_GL_RGBA;
            break;
        case SurfaceFormat::R8G8B8A8:
            if (gl->GetPreferredARGB32Format() == LOCAL_GL_BGRA) {
              // Upload our RGBA as BGRA, but store that the uploaded format is
              // BGRA. (sample from R to get B)
              format = LOCAL_GL_BGRA;
              type = LOCAL_GL_UNSIGNED_INT_8_8_8_8_REV;
              surfaceFormat = SurfaceFormat::B8G8R8A8;
            } else {
              format = LOCAL_GL_RGBA;
              type = LOCAL_GL_UNSIGNED_BYTE;
              surfaceFormat = SurfaceFormat::R8G8B8A8;
            }
            internalFormat = LOCAL_GL_RGBA;
            break;
        case SurfaceFormat::R8G8B8X8:
            // Treat RGBX surfaces as RGBA except for the surface
            // format used.
            if (gl->GetPreferredARGB32Format() == LOCAL_GL_BGRA) {
              format = LOCAL_GL_BGRA;
              type = LOCAL_GL_UNSIGNED_INT_8_8_8_8_REV;
              surfaceFormat = SurfaceFormat::B8G8R8X8;
            } else {
              format = LOCAL_GL_RGBA;
              type = LOCAL_GL_UNSIGNED_BYTE;
              surfaceFormat = SurfaceFormat::R8G8B8X8;
            }
            internalFormat = LOCAL_GL_RGBA;
            break;
        case SurfaceFormat::R5G6B5_UINT16:
            internalFormat = format = LOCAL_GL_RGB;
            type = LOCAL_GL_UNSIGNED_SHORT_5_6_5;
            surfaceFormat = SurfaceFormat::R5G6B5_UINT16;
            break;
        case SurfaceFormat::A8:
            internalFormat = format = LOCAL_GL_LUMINANCE;
            type = LOCAL_GL_UNSIGNED_BYTE;
            // We don't have a specific luminance shader
            surfaceFormat = SurfaceFormat::A8;
            break;
        default:
            MOZ_ASSERT_UNREACHABLE("Unhandled image surface format!");
    }

    if (aOutUploadSize) {
        *aOutUploadSize = 0;
    }

    if (surfaceFormat == gfx::SurfaceFormat::UNKNOWN) {
      return gfx::SurfaceFormat::UNKNOWN;
    }

    if (aNeedInit || !CanUploadSubTextures(gl)) {
        // If the texture needs initialized, or we are unable to
        // upload sub textures, then initialize and upload the entire
        // texture.
        TexImage2DHelper(gl,
                         aTextureTarget,
                         0,
                         internalFormat,
                         aSize.width,
                         aSize.height,
                         aStride,
                         pixelSize,
                         0,
                         format,
                         type,
                         aData);

        if (aOutUploadSize && aNeedInit) {
            uint32_t texelSize = GetBytesPerTexel(internalFormat, type);
            size_t numTexels = size_t(aSize.width) * size_t(aSize.height);
            *aOutUploadSize += texelSize * numTexels;
        }
    } else {
        // Upload each rect in the region to the texture
        for (auto iter = aDstRegion.RectIter(); !iter.Done(); iter.Next()) {
            const IntRect& rect = iter.Get();
            const unsigned char* rectData =
                aData + DataOffset(rect.TopLeft(), aStride, aFormat);

            TexSubImage2DHelper(gl,
                                aTextureTarget,
                                0,
                                rect.x,
                                rect.y,
                                rect.width,
                                rect.height,
                                aStride,
                                pixelSize,
                                format,
                                type,
                                rectData);
        }
    }

    return surfaceFormat;
}

SurfaceFormat
UploadSurfaceToTexture(GLContext* gl,
                       DataSourceSurface* aSurface,
                       const nsIntRegion& aDstRegion,
                       GLuint aTexture,
                       const gfx::IntSize& aSize,
                       size_t* aOutUploadSize,
                       bool aNeedInit,
                       const gfx::IntPoint& aSrcPoint,
                       GLenum aTextureUnit,
                       GLenum aTextureTarget)
{

    int32_t stride = aSurface->Stride();
    SurfaceFormat format = aSurface->GetFormat();
    unsigned char* data = aSurface->GetData() +
        DataOffset(aSrcPoint, stride, format);

    return UploadImageDataToTexture(gl, data, stride, format,
                                    aDstRegion, aTexture, aSize,
                                    aOutUploadSize, aNeedInit,
                                    aTextureUnit, aTextureTarget);
}

bool
CanUploadNonPowerOfTwo(GLContext* gl)
{
    if (!gl->WorkAroundDriverBugs())
        return true;

    // Some GPUs driver crash when uploading non power of two 565 textures.
    return gl->Renderer() != GLRenderer::Adreno200 &&
           gl->Renderer() != GLRenderer::Adreno205;
}

} // namespace gl
} // namespace mozilla
